Nicholas Piggin <npig...@gmail.com> writes:
> Michael Ellerman's on April 11, 2019 12:49 am:
>> On Fri, 2019-03-29 at 07:42:57 UTC, Nicholas Piggin wrote:
>>> Commit 48e7b76957 ("powerpc/64s/hash: Convert SLB miss handlers to C")
>>> broke the radix-mode segment exception handler. In radix mode, this is
>>> exception is not an SLB miss, rather it signals that the EA is outside
>>> the range translated by any page table.
>>>
>>> The commit lost the radix feature alternate code patch, which can
>>> cause faults to some EAs to kernel BUG at arch/powerpc/mm/slb.c:639!
>>>
>>> The original radix code would send faults to slb_miss_large_addr,
>>> which would end up faulting due to slb_addr_limit being 0. This patch
>>> sends radix directly to do_bad_slb_fault, which is a bit clearer.
>>>
>>> Fixes: 48e7b76957 ("powerpc/64s/hash: Convert SLB miss handlers to C")
>>> Cc: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
>>> Reported-by: Anton Blanchard <an...@samba.org>
>>> Signed-off-by: Nicholas Piggin <npig...@gmail.com>
>>> Reviewed-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
>>
>> Applied to powerpc fixes, thanks.
>>
>> https://git.kernel.org/powerpc/c/7100e8704b61247649c50551b965e71d
>
> I sent a v2 with a selftests that triggers the crash if you want it.
> Code was unchanged to no big deal there.
Yeah I checked the kernel part was unchanged so stuck with v1.
I also sent a self test, which is similar but slightly different to
yours, though yours is better in general. I'll try and merge them into
one test.
cheers
